#include <stdio.h>
#include <math.h>
#include <stdbool.h>
+#include <stddef.h>
#include <side/macros.h>
#include <side/endian.h>
/*
* SIDE stands for "Software Instrumentation Dynamically Enabled"
*
- * This is an instrumentation API for Linux user-space, which exposes an
+ * This is an instrumentation ABI for Linux user-space, which exposes an
* instrumentation type system and facilities allowing a kernel or
* user-space tracer to consume user-space instrumentation.
*
- * This instrumentation API exposes 3 type systems:
+ * This instrumentation ABI exposes 3 type systems:
*
* * Stack-copy type system: This is the core type system which can
* represent all supported types and into which all other type systems
* Those dynamic types can be either used as arguments to a variadic
* field list, or as on-stack instrumentation argument for a static
* type SIDE_TYPE_DYNAMIC place holder in the stack-copy type system.
+ *
+ * The extensibility scheme for the SIDE ABI is as follows:
+ *
+ * * Existing field types are never changed nor extended. Field types
+ * can be added to the ABI by reserving a label within
+ * enum side_type_label.
+ * * Existing attribute types are never changed nor extended. Attribute
+ * types can be added to the ABI by reserving a label within
+ * enum side_attr_type.
+ * * Each union part of the ABI has an explicit side defined by a
+ * side_padding() member. Each structure and union have a static
+ * assert validating its size.
+ *
+ * Handling of unknown types by the tracers:
+ *
+ * * A tracer may choose to support only a subset of the types supported
+ * by libside. When encountering an unknown or unsupported type, the
+ * tracer has the option to either disallow the entire event or skip
+ * over the unknown type, both at event registration and when
+ * receiving the side_call arguments.
+ *
+ * * Event descriptions can be extended by adding fields at the end of
+ * the structure. The "struct side_event_description" and "struct
+ * side_event_state" are therefore structures with flexible size and
+ * must not be used within arrays.
*/
-//TODO: as those structures will be ABI, we need to either consider them
-//fixed forever, or think of a scheme that would allow their binary
-//representation to be extended if need be.
+#define SIDE_ABI_VERSION 0
struct side_arg;
struct side_arg_vec;
struct side_arg_dynamic_struct;
struct side_events_register_handle;
struct side_arg_variant;
+struct side_event_state;
+struct side_callback;
enum side_type_label {
/* Stack-copy basic types */
SIDE_TYPE_DYNAMIC_STRUCT_VISITOR,
SIDE_TYPE_DYNAMIC_VLA,
SIDE_TYPE_DYNAMIC_VLA_VISITOR,
+
+ _NR_SIDE_TYPE_LABEL, /* Last entry. */
};
enum side_attr_type {
SIDE_ATTR_TYPE_FLOAT_BINARY64,
SIDE_ATTR_TYPE_FLOAT_BINARY128,
SIDE_ATTR_TYPE_STRING,
+
+ _NR_SIDE_ATTR_TYPE, /* Last entry. */
};
enum side_loglevel {
SIDE_VISITOR_STATUS_ERROR = -1,
};
-//TODO: side_error enum is currently unused.
enum side_error {
SIDE_ERROR_OK = 0,
SIDE_ERROR_INVAL = 1,
typedef enum side_visitor_status (*side_dynamic_struct_visitor_func)(
const struct side_tracer_dynamic_struct_visitor_ctx *tracer_ctx,
void *app_ctx);
+typedef enum side_visitor_status (*side_write_elem_func)(
+ const struct side_tracer_visitor_ctx *tracer_ctx,
+ const struct side_arg *elem);
+typedef enum side_visitor_status (*side_write_field_func)(
+ const struct side_tracer_dynamic_struct_visitor_ctx *tracer_ctx,
+ const struct side_arg_dynamic_field *dynamic_field);
union side_integer_value {
uint8_t side_u8;
int32_t side_s32;
int64_t side_s64;
uintptr_t side_uptr;
+ side_padding(32);
} SIDE_PACKED;
+side_check_size(union side_integer_value, 32);
union side_bool_value {
uint8_t side_bool8;
uint16_t side_bool16;
uint32_t side_bool32;
uint64_t side_bool64;
+ side_padding(32);
} SIDE_PACKED;
+side_check_size(union side_bool_value, 32);
union side_float_value {
#if __HAVE_FLOAT16
#if __HAVE_FLOAT128
_Float128 side_float_binary128;
#endif
+ side_padding(32);
} SIDE_PACKED;
+side_check_size(union side_float_value, 32);
struct side_type_raw_string {
side_ptr_t(const void) p; /* pointer to string */
uint8_t unit_size; /* 1, 2, or 4 bytes */
side_enum_t(enum side_type_label_byte_order, uint8_t) byte_order;
} SIDE_PACKED;
+side_check_size(struct side_type_raw_string, 18);
struct side_attr_value {
side_enum_t(enum side_attr_type, uint32_t) type;
struct side_type_raw_string string_value;
union side_integer_value integer_value;
union side_float_value float_value;
+ side_padding(32);
} SIDE_PACKED u;
};
+side_check_size(struct side_attr_value, 36);
/* User attributes. */
struct side_attr {
const struct side_type_raw_string key;
const struct side_attr_value value;
} SIDE_PACKED;
+side_check_size(struct side_attr, 54);
/* Type descriptions */
struct side_type_null {
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_null, 20);
struct side_type_bool {
side_ptr_t(const struct side_attr) attr;
uint16_t len_bits; /* bits. 0 for (bool_size * CHAR_BITS) */
side_enum_t(enum side_type_label_byte_order, uint8_t) byte_order;
} SIDE_PACKED;
+side_check_size(struct side_type_bool, 25);
struct side_type_byte {
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_byte, 20);
struct side_type_string {
side_ptr_t(const struct side_attr) attr;
uint8_t unit_size; /* 1, 2, or 4 bytes */
side_enum_t(enum side_type_label_byte_order, uint8_t) byte_order;
} SIDE_PACKED;
+side_check_size(struct side_type_string, 22);
struct side_type_integer {
side_ptr_t(const struct side_attr) attr;
uint8_t signedness; /* true/false */
side_enum_t(enum side_type_label_byte_order, uint8_t) byte_order;
} SIDE_PACKED;
+side_check_size(struct side_type_integer, 26);
struct side_type_float {
side_ptr_t(const struct side_attr) attr;
uint16_t float_size; /* bytes */
side_enum_t(enum side_type_label_byte_order, uint8_t) byte_order;
} SIDE_PACKED;
+side_check_size(struct side_type_float, 23);
struct side_enum_mapping {
int64_t range_begin;
int64_t range_end;
struct side_type_raw_string label;
} SIDE_PACKED;
+side_check_size(struct side_enum_mapping, 16 + sizeof(struct side_type_raw_string));
struct side_enum_mappings {
side_ptr_t(const struct side_enum_mapping) mappings;
uint32_t nr_mappings;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_enum_mappings, 40);
struct side_enum_bitmap_mapping {
uint64_t range_begin;
uint64_t range_end;
struct side_type_raw_string label;
} SIDE_PACKED;
+side_check_size(struct side_enum_bitmap_mapping, 16 + sizeof(struct side_type_raw_string));
struct side_enum_bitmap_mappings {
side_ptr_t(const struct side_enum_bitmap_mapping) mappings;
uint32_t nr_mappings;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_enum_bitmap_mappings, 40);
struct side_type_struct {
side_ptr_t(const struct side_event_field) fields;
uint32_t nr_fields;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_struct, 40);
struct side_type_array {
side_ptr_t(const struct side_type) elem_type;
uint32_t length;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_array, 40);
struct side_type_vla {
side_ptr_t(const struct side_type) elem_type;
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_vla, 36);
struct side_type_vla_visitor {
side_ptr_t(const struct side_type) elem_type;
- side_visitor_func visitor;
+ side_func_ptr_t(side_visitor_func) visitor;
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_type_vla_visitor, 52);
struct side_type_enum {
side_ptr_t(const struct side_enum_mappings) mappings;
side_ptr_t(const struct side_type) elem_type;
} SIDE_PACKED;
+side_check_size(struct side_type_enum, 32);
struct side_type_enum_bitmap {
side_ptr_t(const struct side_enum_bitmap_mappings) mappings;
side_ptr_t(const struct side_type) elem_type;
} SIDE_PACKED;
+side_check_size(struct side_type_enum_bitmap, 32);
struct side_type_gather_bool {
uint64_t offset; /* bytes */
+ uint16_t offset_bits; /* bits */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_bool type;
- uint16_t offset_bits; /* bits */
} SIDE_PACKED;
+side_check_size(struct side_type_gather_bool, 11 + sizeof(struct side_type_bool));
struct side_type_gather_byte {
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_byte type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_byte, 9 + sizeof(struct side_type_byte));
struct side_type_gather_integer {
uint64_t offset; /* bytes */
+ uint16_t offset_bits; /* bits */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_integer type;
- uint16_t offset_bits; /* bits */
} SIDE_PACKED;
+side_check_size(struct side_type_gather_integer, 11 + sizeof(struct side_type_integer));
struct side_type_gather_float {
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_float type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_float, 9 + sizeof(struct side_type_float));
struct side_type_gather_string {
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_string type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_string, 9 + sizeof(struct side_type_string));
struct side_type_gather_enum {
side_ptr_t(const struct side_enum_mappings) mappings;
side_ptr_t(const struct side_type) elem_type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_enum, 32);
struct side_type_gather_struct {
+ side_ptr_t(const struct side_type_struct) type;
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
- side_ptr_t(const struct side_type_struct) type;
uint32_t size; /* bytes */
} SIDE_PACKED;
+side_check_size(struct side_type_gather_struct, 29);
struct side_type_gather_array {
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_array type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_array, 9 + sizeof(struct side_type_array));
struct side_type_gather_vla {
side_ptr_t(const struct side_type) length_type; /* side_length() */
-
uint64_t offset; /* bytes */
uint8_t access_mode; /* enum side_type_gather_access_mode */
struct side_type_vla type;
} SIDE_PACKED;
+side_check_size(struct side_type_gather_vla, 25 + sizeof(struct side_type_vla));
struct side_type_gather {
union {
struct side_type_gather_array side_array;
struct side_type_gather_vla side_vla;
struct side_type_gather_struct side_struct;
+ side_padding(61);
} SIDE_PACKED u;
} SIDE_PACKED;
+side_check_size(struct side_type_gather, 61);
struct side_type {
- side_enum_t(enum side_type_label, uint32_t) type;
+ side_enum_t(enum side_type_label, uint16_t) type;
union {
/* Stack-copy basic types */
struct side_type_null side_null;
/* Gather types */
struct side_type_gather side_gather;
+ side_padding(62);
} SIDE_PACKED u;
} SIDE_PACKED;
+side_check_size(struct side_type, 64);
struct side_variant_option {
int64_t range_begin;
int64_t range_end;
const struct side_type side_type;
} SIDE_PACKED;
+side_check_size(struct side_variant_option, 16 + sizeof(const struct side_type));
struct side_type_variant {
- const struct side_type selector;
side_ptr_t(const struct side_variant_option) options;
side_ptr_t(const struct side_attr) attr;
uint32_t nr_options;
uint32_t nr_attr;
+ const struct side_type selector;
} SIDE_PACKED;
+side_check_size(struct side_type_variant, 40 + sizeof(const struct side_type));
struct side_event_field {
side_ptr_t(const char) field_name;
struct side_type side_type;
} SIDE_PACKED;
+side_check_size(struct side_event_field, 16 + sizeof(struct side_type));
enum side_event_flags {
SIDE_EVENT_FLAG_VARIADIC = (1 << 0),
};
-struct side_callback {
- union {
- void (*call)(const struct side_event_description *desc,
- const struct side_arg_vec *side_arg_vec,
- void *priv);
- void (*call_variadic)(const struct side_event_description *desc,
- const struct side_arg_vec *side_arg_vec,
- const struct side_arg_dynamic_struct *var_struct,
- void *priv);
- } SIDE_PACKED u;
- void *priv;
-} SIDE_PACKED;
-
union side_arg_static {
/* Stack-copy basic types */
union side_bool_value bool_value;
side_ptr_t(const void) ptr;
side_ptr_t(const void) length_ptr;
} SIDE_PACKED side_vla_gather;
+ side_padding(32);
} SIDE_PACKED;
+side_check_size(union side_arg_static, 32);
struct side_arg_dynamic_vla {
side_ptr_t(const struct side_arg) sav;
uint32_t len;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_arg_dynamic_vla, 40);
struct side_arg_dynamic_struct {
side_ptr_t(const struct side_arg_dynamic_field) fields;
uint32_t len;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_arg_dynamic_struct, 40);
struct side_dynamic_struct_visitor {
- void *app_ctx;
- side_dynamic_struct_visitor_func visitor;
+ side_func_ptr_t(side_dynamic_struct_visitor_func) visitor;
+ side_ptr_t(void) app_ctx;
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_dynamic_struct_visitor, 52);
struct side_dynamic_vla_visitor {
- void *app_ctx;
- side_visitor_func visitor;
+ side_func_ptr_t(side_visitor_func) visitor;
+ side_ptr_t(void) app_ctx;
side_ptr_t(const struct side_attr) attr;
uint32_t nr_attr;
} SIDE_PACKED;
+side_check_size(struct side_dynamic_vla_visitor, 52);
union side_arg_dynamic {
/* Dynamic basic types */
struct side_dynamic_struct_visitor side_dynamic_struct_visitor;
struct side_dynamic_vla_visitor side_dynamic_vla_visitor;
+
+ side_padding(58);
} SIDE_PACKED;
+side_check_size(union side_arg_dynamic, 58);
struct side_arg {
- side_enum_t(enum side_type_label, uint32_t) type;
+ side_enum_t(enum side_type_label, uint16_t) type;
union {
union side_arg_static side_static;
union side_arg_dynamic side_dynamic;
+ side_padding(62);
} SIDE_PACKED u;
} SIDE_PACKED;
+side_check_size(struct side_arg, 64);
struct side_arg_variant {
struct side_arg selector;
struct side_arg option;
} SIDE_PACKED;
+side_check_size(struct side_arg_variant, 128);
struct side_arg_vec {
side_ptr_t(const struct side_arg) sav;
uint32_t len;
} SIDE_PACKED;
+side_check_size(struct side_arg_vec, 20);
struct side_arg_dynamic_field {
side_ptr_t(const char) field_name;
const struct side_arg elem;
} SIDE_PACKED;
-
-/* The visitor pattern is a double-dispatch visitor. */
-struct side_tracer_visitor_ctx {
- enum side_visitor_status (*write_elem)(
- const struct side_tracer_visitor_ctx *tracer_ctx,
- const struct side_arg *elem);
- void *priv; /* Private tracer context. */
-} SIDE_PACKED;
-
-struct side_tracer_dynamic_struct_visitor_ctx {
- enum side_visitor_status (*write_field)(
- const struct side_tracer_dynamic_struct_visitor_ctx *tracer_ctx,
- const struct side_arg_dynamic_field *dynamic_field);
- void *priv; /* Private tracer context. */
-} SIDE_PACKED;
-
-/*
- * This structure is _not_ packed to allow atomic operations on its
- * fields.
- */
-struct side_event_state {
- uintptr_t enabled;
- const struct side_callback *callbacks;
-};
+side_check_size(struct side_arg_dynamic_field, 16 + sizeof(const struct side_arg));
struct side_event_description {
+ uint32_t struct_size; /* Size of this structure. */
+ uint32_t version; /* ABI version. */
+
side_ptr_t(struct side_event_state) state;
side_ptr_t(const char) provider_name;
side_ptr_t(const char) event_name;
side_ptr_t(const struct side_event_field) fields;
side_ptr_t(const struct side_attr) attr;
uint64_t flags;
- uint32_t version;
+ uint16_t nr_side_type_label;
+ uint16_t nr_side_attr_type;
side_enum_t(enum side_loglevel, uint32_t) loglevel;
uint32_t nr_fields;
uint32_t nr_attr;
uint32_t nr_callbacks;
+#define side_event_description_orig_abi_last nr_callbacks
+ /* End of fields supported in the original ABI. */
+
+ char end[]; /* End with a flexible array to account for extensibility. */
} SIDE_PACKED;
+/*
+ * This structure is _not_ packed to allow atomic operations on its
+ * fields.
+ */
+struct side_event_state {
+ uint32_t struct_size; /* Size of this structure. */
+ uint32_t enabled;
+ side_ptr_t(const struct side_callback) callbacks;
+ side_ptr_t(struct side_event_description) desc;
+
+ char end[]; /* End with a flexible array to account for extensibility. */
+};
+
/* Event and type attributes */
#define side_attr(_key, _value) \
.u = { \
.side_vla_visitor = { \
.elem_type = SIDE_PTR_INIT(_elem_type), \
- .visitor = _visitor, \
+ .visitor = SIDE_PTR_INIT(_visitor), \
.attr = SIDE_PTR_INIT(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
}, \
.u = { \
.side_dynamic = { \
.side_dynamic_vla_visitor = { \
- .app_ctx = _ctx, \
- .visitor = _dynamic_vla_visitor, \
+ .app_ctx = SIDE_PTR_INIT(_ctx), \
+ .visitor = SIDE_PTR_INIT(_dynamic_vla_visitor), \
.attr = SIDE_PTR_INIT(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
}, \
.u = { \
.side_dynamic = { \
.side_dynamic_struct_visitor = { \
- .app_ctx = _ctx, \
- .visitor = _dynamic_struct_visitor, \
+ .app_ctx = SIDE_PTR_INIT(_ctx), \
+ .visitor = SIDE_PTR_INIT(_dynamic_struct_visitor), \
.attr = SIDE_PTR_INIT(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
}, \
.sav = SIDE_PTR_INIT(side_sav), \
.len = SIDE_ARRAY_SIZE(side_sav), \
}; \
- side_call(&(_identifier), &side_arg_vec); \
+ side_call(&(side_event_state__##_identifier), &side_arg_vec); \
}
#define side_event(_identifier, _sav) \
.len = SIDE_ARRAY_SIZE(side_fields), \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
}; \
- side_call_variadic(&(_identifier), &side_arg_vec, &var_struct); \
+ side_call_variadic(&(side_event_state__##_identifier), &side_arg_vec, &var_struct); \
}
#define side_event_variadic(_identifier, _sav, _var, _attr...) \
side_event_call_variadic(_identifier, SIDE_PARAM(_sav), SIDE_PARAM(_var), SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list()))
#define _side_define_event(_linkage, _identifier, _provider, _event, _loglevel, _fields, _flags, _attr...) \
+ _linkage struct side_event_description __attribute__((section("side_event_description"))) \
+ _identifier; \
_linkage struct side_event_state __attribute__((section("side_event_state"))) \
side_event_state__##_identifier = { \
+ .struct_size = offsetof(struct side_event_state, end), \
.enabled = 0, \
- .callbacks = &side_empty_callback, \
+ .callbacks = SIDE_PTR_INIT(&side_empty_callback), \
+ .desc = SIDE_PTR_INIT(&(_identifier)), \
}; \
_linkage struct side_event_description __attribute__((section("side_event_description"))) \
_identifier = { \
+ .struct_size = offsetof(struct side_event_description, end), \
+ .version = SIDE_ABI_VERSION, \
.state = SIDE_PTR_INIT(&(side_event_state__##_identifier)), \
.provider_name = SIDE_PTR_INIT(_provider), \
.event_name = SIDE_PTR_INIT(_event), \
.fields = SIDE_PTR_INIT(_fields), \
.attr = SIDE_PTR_INIT(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
.flags = (_flags), \
- .version = 0, \
+ .nr_side_type_label = _NR_SIDE_TYPE_LABEL, \
+ .nr_side_attr_type = _NR_SIDE_ATTR_TYPE, \
.loglevel = SIDE_ENUM_INIT(_loglevel), \
.nr_fields = SIDE_ARRAY_SIZE(SIDE_PARAM(_fields)), \
.nr_attr = SIDE_ARRAY_SIZE(SIDE_PARAM_SELECT_ARG1(_, ##_attr, side_attr_list())), \
extern "C" {
#endif
+struct side_callback {
+ union {
+ void (*call)(const struct side_event_description *desc,
+ const struct side_arg_vec *side_arg_vec,
+ void *priv);
+ void (*call_variadic)(const struct side_event_description *desc,
+ const struct side_arg_vec *side_arg_vec,
+ const struct side_arg_dynamic_struct *var_struct,
+ void *priv);
+ } SIDE_PACKED u;
+ void *priv;
+} SIDE_PACKED;
+
+/* The visitor pattern is a double-dispatch visitor. */
+struct side_tracer_visitor_ctx {
+ side_write_elem_func write_elem;
+ void *priv; /* Private tracer context. */
+} SIDE_PACKED;
+
+struct side_tracer_dynamic_struct_visitor_ctx {
+ side_write_field_func write_field;
+ void *priv; /* Private tracer context. */
+} SIDE_PACKED;
+
extern const struct side_callback side_empty_callback;
-void side_call(const struct side_event_description *desc,
+void side_call(const struct side_event_state *state,
const struct side_arg_vec *side_arg_vec);
-void side_call_variadic(const struct side_event_description *desc,
+void side_call_variadic(const struct side_event_state *state,
const struct side_arg_vec *side_arg_vec,
const struct side_arg_dynamic_struct *var_struct);
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